Nitrogen trifluoride (NF.sub.3) is a colorless gas under normal conditions and has a boiling point of about -129.degree. C. and a melting point of about -208.degree. C. Nitrogen trifluoride (NF.sub.3) has little odor. However, commercial grades contaminated with trace levels of active fluorides have a pungent, musty odor. NF.sub.3 is an oxidizer that is thermodynamically stable at elevated temperatures. At temperatures up to about 662.degree. F. (350.degree. C.), its reactivity is comparable to oxygen. At higher temperatures, its reactivity is similar to fluorine owing to appreciable dissociation into NF.sub.2.sup.+ and F.sup.-. The thermal dissociation of NF.sub.3 has been found to peak in the temperature range of 1100.degree. to 15000.degree. Kelvin. NF.sub.3 acts primarily upon the elements as a fluorinating agent, but not a very active one at lower temperatures. At elevated temperatures, NF.sub.3 pyrolyzes with many of the elements to produce nitrogen tetrafluoride (N.sub.2 F.sub.4) and the corresponding fluoride. The pyrolysis of NF.sub.3 over copper turnings produces N.sub.2 F.sub.4 in a 62-71% yield at 707.degree. F. (375.degree. C.). Pyrolysis over carbon is more favorable. Hydrogen reacts with NF.sub.3 with the rapid liberation of large amounts of heat and is the basis for the use of NF.sub.3 in high-energy chemical lasers. The flammability range for NF.sub.3 /H.sub.2 mixtures is 9.4-95 mole % of NF.sub.3. NF.sub.3 reacts with organic compounds, but generally an elevated temperature is required to initiate the reaction. Under these conditions, the reaction will often proceed explosively and great care must be exercised when exposing NF.sub.3 to organic compounds. Therefore, NF.sub.3 has found little use as a fluorinating agent for organic compounds.
Nitrogen trifluoride has been used successfully in large quantities as a fluorine source for high energy chemical lasers. It is preferred over fluorine because of its comparative ease of handling at ambient conditions. NF.sub.3 has been used as a source of fluorine in the preparation of fluoroolefins, and as an oxidizer for high energy level. Recently, an increasing amount of NF.sub.3 is being used in the semi-conductor industry as a cleaning agent and as a dry etchant, showing significantly higher etching rates and selectivities when compared to carbon tetrafluoride (CF.sub.4) and mixtures of CF.sub.4 and oxygen. It is used to clean semiconductor micro chips and silicon wafers. Minor amounts of NF.sub.3 are used as a chemical intermediate in the production of tetrafluorohydrazine and a series of perfluoroammonium salts. NF.sub.3 was also used as an oxidizer in rocketry in the early 1960's, but this application was not commercialized.
There remains a need for an efficient manufacturing apparatus and method for the continuous production and generation of nitrogen trifluoride (NF.sub.3) while producing no by-products.